1. Field of the Invention
The present invention relates generally to switching regulator power supplies for producing regulated DC power at low voltages and high amperages, and, more particularly, the present invention relates to switching regulator power supplies which are regulated by a control circuit receiving a feedback voltage from the output.
2. Description of the Prior Art
Switching regulator power supplies for producing electric power at regulated DC voltages and high amperages are well known in the art. An example of such a power supply is described in U.S. Pat. No. 3,573,597 issued to Genuit et al on Apr. 6, 1971 and entitled "High Current Switching Regulator with Overlapping Output Current Pulses". Genuit shows and describes a switching regulator circuit which is adapted for operation from an unregulated high voltage DC source. The circuit of Genuit utilizes a plurality of silicon control rectifiers (SCR) and inductive reactors with sequential gating of the rectifiers at regulator intervals for supplying overlapping output current pulses from the reactors to generate high output currents at low voltages with relatively low ripple currents. A standard .pi. filtering network is shown in Genuit which comprises a choke and two filter capacitors. The capacitors are connected at one end to the negative output of the switched apparatus of the switching regulator circuit. The filter capacitors have their other opposite ends connected to the input and output, respectively, of the choke. The choke is connected in series with the positive output of the switched apparatus.
U.S. Pat. No. 4,142,231 issued to Wilson et al on Feb. 27, 1979 and entitled "High Current Low Voltage Liquid Cooled Switching Regulator DC Power Supply", shows and describes a cooling system for a switching regulator circuit. The output of the switching regulator circuit is applied to two plates, one plate being positive, the other opposite plate being negative. The positive and negative plates are liquid cooled to provide the proper operating temperatures for the components.
Both the Wilson and Genuit patents show a control circuit which applies the necessary pulses to the gates of the silicon controlled rectifiers (hereinafter referred to as SCR) to render the SCR conductive. The control circuit as shown in Genuit is connected to the output of the switching regulator circuit for receiving a feedback voltage therefrom. The control circuitry varies the timing of the pulses to the various gates of the SCRs in order to maintain the voltage at the output at the desired level. The prior constructions of switching regulator circuits and more specifically the control units therefor do not utilize a feedback voltage which has the phase shift which is induced in the output by the choke, eliminated therefrom. It has been found to be desirable to eliminate the phase shift induced in the output voltage by the choke from the feedback circuit to the control circuit to provide for greater stability in the output at lower currents.